WikimediaUI theme: Reduce Checkbox*- & RadioSelectInputWidget vertical space
WikimediaUI theme: Reduce Checkbox*- & RadioSelectInputWidget vertical space

Reducing vertical space taken up by CheckboxMultiselectInputWidget &
RadioSelectInputWidget to be in on par with their JS siblings.

Bug: T177683
Change-Id: Ib00af2f05ba8e3a92c7343e00f5fc438bbb73531

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui